The present invention relates to a method for manufacturing a crystalline electron emitting device by a sputtering method using a target having the sintered body of low work function substance, in particular a boron lanthanum compound, and a computer memory medium or recording medium thereof.
As disclosed in Patent Documents 1, 2, and 3, as a secondary electron emission film, a thin film of a boron lanthanum compound such as LaB6 is known. Further, as disclosed in Patent Documents 1, 2, and 3, it is also known that the crystalline thin film of a boron lanthanum compound is deposited by using the sputtering method. Further, as disclosed in Patent Document 4, it is also known that, as a target used by the sputtering method, a sintered body of the boron lanthanum compound such as LaB6 is used.
Patent Document 1: Japanese Patent Application Laid-Open No. H1-286228
Patent Document 2: Japanese Patent Application Laid-Open No. H3-232959
Patent Document 3: Japanese Patent Application Laid-Open No. H3-101033
Patent Document 4: Japanese Patent Application Laid-Open No. H6-248446
However, when a boron lanthanum compound thin film is exposed to the atmosphere after the deposition by a sputtering apparatus, it is oxidized. When this oxidized boron lanthanum compound thin film is used for the electron emitting device such as a FED (Field Emission Display) and a SED (Surface-Conduction Electron-emitter Display), it has been hard to obtain sufficient luminance as a display device.
An object of the present invention is to provide an electron emitting device having sufficient luminance using a boron lanthanum compound thin film.
The first aspect of the present invention is a manufacturing method of an electron emitting device, comprising: a first step of preparing a first substrate disposed with phosphors and disposing it in a vacuum or reduced pressure atmosphere; a second step of disposing an electron emitting base member on a second substrate; third step of disposing a mask for opening a first region including said electron emitting base member and screening a second region not including said electron emitting base member, in a state in which a vacuum or reduced pressure atmosphere is maintained from said second step; a fourth step of accumulating sputtered particles on the second substrate subjected to said second step by a sputtering method using a target having a low work function substance in a state in which the vacuum or reduced pressure atmosphere is maintained from said third step; and a fifth step of making the first substrate subjected to said first step oppose to the second substrate subjected to said fourth step and sealing the first substrate and the second substrate by a sealing agent to fabricate a vacuum or reduced pressure chamber, in a state in which the vacuum or reduced pressure atmosphere is maintained from said first step and said fourth step.
The second aspect of the present invention is a memory medium or a recording medium for the manufacturing of an electron emitting device, comprising a control program for executing: a first step of preparing a first substrate disposed with phosphors and disposing it in a vacuum or reduced pressure atmosphere; a second step of disposing an electron emitting base member on a second substrate; a third step of disposing a mask for opening a first region including said electron emitting base member and screening a second region not including said electron emitting base member, in a state in which a vacuum or reduced pressure atmosphere is maintained from said second step; a fourth step of accumulating sputtered particles on the second substrate subjected to said second step by a sputtering method using a target having a low work function substance in a state in which the vacuum or reduced pressure atmosphere is maintained from said third step; and a fifth step of making the first substrate subjected to said first step oppose to the second substrate subjected to said fourth step and sealing the first substrate and the second substrate by a sealing agent to fabricate a vacuum or reduced pressure chamber, in a state in which the vacuum or reduced pressure atmosphere is maintained from said first step and said fourth step.
According to the present invention, the crystalline thin film of a boron lanthanum compound such as LaB6 can be sealed in a vacuum chamber without being oxidized, thereby a display device having high luminance can be realized.
1 First Chamber
2 Second Chamber
5, 51, 52, 53, 54, 55 Gate Valve
11 Target
12 Substrate
13, 15, 42, 43 Substrate Holder
14 Sputter Gas Introducing System
16 Heating Mechanism
17 Plasma Electrode
18 Plasma Source Gas Introducing System
19 Sputtering High Frequency Power Source System
191, 221, 502 Blocking Capacitor
192, 222, 503 Matching Circuit
193, 223, 504 High Frequency Power Source
194 Sputtering DC Power Source (First DC Bias Power Source)
20 (Annealing) Substrate Bias Power Source (Third DC Power Source)
21 Substrate Bias Power Source (Second DC Power Source)
22 Plasma Source High Frequency Power Source System
23, 501 LF Cut Filter for Cutting LF Components from HF Power Source 193
24 HF Cut Filter
101 Cathode
102 Magnetic Field Generator
103 Magnetic Field Region
201, 207 Glass Substrate
202 Cathode Electrode
203 LaB6 Thin Film
204 Vacuum Space (or Atmosphere)
205 Anode Electrode
206 Phosphor Film
208 Electron Source Substrate
209 Projection
210 Phosphor Substrate
211 DC Power Source
401 Vacuum Mask Loading Apparatus
402 Magnetron Sputtering Apparatus
403 Assemble Device in Vacuum Space
404 First Load Lock Chamber
405, 406, 407, 408, 409 Gate Valve
410 Computer
411 Arithmetic Operation Circuit Unit
413, 414, 415, 416, 417, 418, 419, 420 Control Bus Line
421 Memory Unit
412 Time Control Unit
51 Mask Opening Unit
52 Mask
601 Display-side Substrate
602 Three Primary Color Phosphor Matrix
603 Black Matrix
604 Anode Electrode
605 Spacer
606 Rear Face Substrate
607 Insulator Film
608 Scan Line
609 Signal Line
610 Hole Containing Electron Emitting Device inside thereof
In the present invention, the target 11 containing a boron atom (B) and a lanthanum atom (La) such as LaB6 is used.
The substrate 12 is placed on the holder 13 inside the first chamber 1, and the substrate 12 is opposed to the cathode 101, and is subjected to vacuum exhaust and heating (increased up to the temperature of the sputtering time later) inside the chamber. The heating is performed by the heating mechanism 16. Next, a plasma source gas (helium gas, argon gas, krypton gas, xenon gas) is introduced from the sputtering gas introducing system 14, and is set to the predetermined pressure (0.01 Pa to 50 Pa, and preferably 0.1 Pa to 10 Pa), and after that, a deposition is started by using the sputter power source 19.
Next, by applying a high frequency power from a high frequency power source 193 (the frequency is 0.1 MHz to 10 GHz, and preferably 1 MHz to 5 GHz, and the input power is 100 W to 3000 W, and preferably 200 W to 2000 W), plasma is generated, and in the first DC power source 194, a DC power (voltage) is set to the predetermined voltage (−50 V to −1000 V, and preferably −10 V to −500 V), thereby to perform a sputter deposition. At the substrate 12 side, the substrate holder 13 is applied with the DC power (voltage) by the predetermined voltage (0 V to −500 V, and preferably −10 V to −100 V) by the second DC power source 21. The DC power (first DC power) from the first DC power source 194 may be inputted before applying the high frequency power from the high frequency power source 193, and may be inputted simultaneously with the application of the high frequency power, and may be continuously inputted after completing the application of the high frequency power.
An input position to the cathode 101 of the DC power and/or the high frequency power from the second DC power source 21 and/or the sputtering high frequency power source 19 is preferably set to a plurality of points symmetrical to the center point of the cathode 101. For example, the position symmetrical to the center point of the cathode 101 may be set to a plurality of input positions of the DC power and/or the high frequency power.
The magnetic field generator 102 formed by a permanent magnet and an electromagnet is positioned and located at the rear of the cathode 101, and can expose the surface of the target 11 to a magnetic field 103. While the magnetic field 103 preferably does not reach up to the surface of the substrate 12, if it is to the extent of not narrowing an extensive single-crystal domain of the boron lanthanum compound, the magnetic field 103 may reach the surface of the substrate 12.
An HF cut filter 24 provided at the side of the first DC power source 194 used in the present invention can protect the first DC power source 194 as another effect.
A south pole and a north pole of the magnetic field generating means 102 can be mutually disposed as a opposite polarity in a vertical direction to the flat surface of the cathode 103. At this time, adjacent magnets are made mutually into a opposite polarity in a horizontal direction to the flat surface of the cathode 103. Further, the south pole and the north pole of the magnetic field generating means 102 can also be mutually disposed as a opposite polarity in the horizontal direction to the flat surface of the cathode 103. At this time also, the adjacent magnets are mutually made into a opposite polarity in the horizontal direction to the flat surface of the cathode 103.
In the preferred mode of the present invention, the magnetic field generating means 102 can perform a reciprocation motion in the horizontal direction to the cathode 101 or the surface of the target 11.
The filter 23 used in the present invention can cut a low frequency component (0.01 MHz or less, particularly, the frequency component 0.001 MHz or less) from the high frequency power source 193.
Further, the present invention can extend an average area of the single-crystal domain by applying the DC power (voltage) from the second DC power source 21 of the substrate 12 side to the substrate holder 13. This second DC power (voltage) may be a pulse waveform power having a DC component (DC component to the ground) in an hourly average.
In
In the present invention, as the electron emitting base member, it is not limited to the above described, and in addition, it may be a SED type electron emitting base member using the thin film (PdO thin film, crystal carbon thin film, and the like) forming a nano scale gap by a forming process.
A step 302 is a step in which the first glass substrate is transferred into a first vacuum chamber forming a first vacuum or reduced pressure atmosphere (hereinafter, both of “vacuum” and “reduced pressure atmosphere” are referred to as “vacuum”). At the time of transferring, an ordinary load lock chamber (not shown) and a gate valve (not shown) can be used.
A step 303 is a step in which a second glass substrate provided with the electron emitting base member is prepared. This electron emitting base member is disposed at an intersecting point with the scan line and the signal line on an equivalent circuit, and is provided for a matrix drive. While the electron emitting base member has an electron emission effect by itself, its electron emission efficiency can be improved to a large extent by the low work function substance film of the later step.
The electron emitting base member of one section together with the phosphor film of one section forms one sub-pixel. Three color pixels of one red sub-pixel, one green sub-pixel and one blue sub-pixel form one-pixel. In the present invention, the one-pixel is disposed at a plurality of columns along a plurality of rows, thereby a matrix-array can be formed. In this matrix array, a metal film wiring (aluminum wiring, copper wiring, silver wiring, and the like) for the scan line and a metal film wiring (aluminum wiring, copper wiring, silver wiring, and the like) for the signal line are formed.
Further, to the second glass substrate used in the present invention, an antistatic film (charge dissipation film) for charging an electrostatic charge generated during a manufacturing step or the operation as a display device can be preferably provided. As this antistatic film, a titanium oxide film, a tin oxide film, an indium oxide film, an indium/tin oxide film (ITO film), and the like can be used.
Further, the second glass substrate used in the present invention can also be provided with a spacer and a sealing agent in advance.
In a step 304, the second glass substrate is transferred into the second vacuum chamber of a second vacuum atmosphere. At the time of transferring, a known load lock chamber (not shown) and gate valve (not shown) can be used.
A step 305 is a step in which the second glass substrate is provided with a mask 52 of
As the mask 52, while a stainless mask and an aluminum mask are preferably used, it is not limited to them.
In order to maintain airtightness with the second glass substrate, it is possible to apply a vacuum chuck mechanism and an electrostatic chuck mechanism to the mask 52.
A step 306 is a step in which a boron lanthanum compound film such as LaB6 is provided on the second glass substrate by using a sputtering apparatus (magnetron sputtering apparatus, high frequency RF magnetron sputtering apparatus, and the like shown in
By the step 306, the boron lanthanum compound film such as LaB6 is located entirely or partially of the second glass substrate, and as a result, the electron emitting base member is coated by the boron lanthanum compound film such as LaB6 which is the low work function substance film, and the mask is isolated and removed from the second glass substrate.
An LaB6 film is not formed on The second region not including the electron emitting base member. As a result, at the time of displaying, an unnecessary light emission due to the electron generated from the LaB6 film of the second region, which becomes an unnecessary electron source other than the pixel, does not occur. Hence, display of high display quality having no reduction in display contrast and no flickering light caused by this can be obtained.
Further, in addition, the present invention can use, for example, a CeB6 film, a BaLaB6 film, a carbon containing LaB6 film, and the like as a low work function substance film.
In a step 307, the first glass substrate of the step 302 and the second glass substrate of the step 306 are transferred into a fourth chamber of a fourth vacuum atmosphere while maintaining each glass substrate in a vacuum state. The first vacuum atmosphere, the third vacuum atmosphere, and the fourth vacuum atmosphere are vacuum-connected by a gate valve (not shown).
In a step 308, the first glass substrate and the second glass substrate are oppositely placed at the predetermined interval inside the fourth chamber, the position of the phosphor film of one section and the position of the electron emitting base member of one section are matched accurately, and they are sealed by using a sealing agent. The predetermined interval is decided by the spacer provided in advance. The spacer may be column-like or plate-like, and is disposed at every predetermined interval. The sealing agent is provided at the first glass substrate or the second glass substrate in advance, and can be sealed to form a vacuum atmosphere between the first glass substrate and the second glass substrate. As the sealing agent, a low melting point metal (for example, iridium and tin) and an organic resin adhesive, and the like can be preferably used.
In the step 308, the first glass substrate and the second glass substrate are held by the known electrostatic chuck and vacuum chuck, and in a state in which both substrates are spaced at a sufficient distance, they are subjected to vacuum bake processing and can be adhered with a gettering material such as barium and titan. After that, both substrates are made close to the interval decided by the spacer material, and after that, are subjected to the sealing work processing, thereby a vacuum display panel is manufactured.
The first glass substrate provided with the phosphor film is transferred into the second load lock chamber 405, and after vacuum-exhausting the inside of the chamber 405, the gate valve 409 is opened, and is transferred into the chamber apparatus 403 for transferring phosphor substrate in vacuum atmosphere.
The second glass substrate provided with the electron emitting base member is transferred into the first load lock chamber 404, and after vacuum-exhausting the inside of the chamber 401, the gate valve 406 is opened, and the second glass substrate is positioned inside the vacuum chamber 401. The mask (illustrated in
After completing the step 304, the gate valve 407 is opened, and in a state in which the mask 52 is held, the second glass substrate is transferred into the magnetron sputtering apparatus 402. The magnetron sputtering apparatus 402 performs the step 306, and can provide the LaB6 film in the region including the electron emitting base member.
The computer 410 has a memory unit 421, and can control all the steps from the steps 301 to 308. As the memory unit 421, it is possible to use a recording medium such as a hard disc medium, a magneto-optic disc medium, and a floppy (registered trademark) disc medium, and a non-volatile memory (memory medium) such as a flash memory and an MRAM, and the memory unit 421 can temporarily memorize the data from the non-volatile memory. The memory unit 421 stores a control program for controlling all the steps from the steps 301 to 308. The stored control program data is processed by the arithmetic operation circuit unit (CPU: Central Arithmetic Circuit) 411, and these processed data are transmitted as illustrated through the control bus lines 413, 414, 415, 416, 417, 418, 419, and 420.
Further, in the present invention, a time control unit 412 (for example, generates a control signal by using a clock from a wave clock) is located inside the arithmetic operation circuit unit 411, so that all the steps 301 to 308 can be accurately controlled.
Further, in the present invention, as the magnet unit used in the magnetron sputtering, a permanent magnet which is commonly used can be used.
Further, when the magnetron sputtering is performed by stopping the movement of the tray, a target having an area slightly larger than the substrate 12 is prepared, and a plurality of magnet units are disposed on the rear surface of the target spaced at appropriate intervals, and they are made to perform a translation motion in the direction parallel to the target surface, so that good thickness uniformity and a high rate of target utilization can be obtained. Further, when performing the sputtering while moving the tray, with respect to the moving direction of the substrate, the target and the magnet unit having a short width as compared with a length of the substrate can be used.
The scan line 608 and the signal line 609 are matrix-driven by a scan side drive circuit (not shown) and a signal side drive circuit (not shown), respectively. This matrix-drive is such that a scan signal is applied to the scan line 608 and an image signal synchronized with the scan signal is applied to the signal line 609, thereby displaying an image.
This application is a continuation application of International Application No. PCT/JP2008/061753, filed on Jun. 27, 2008, the entire contents of which are incorporated by reference herein.
Number | Date | Country | |
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Parent | PCT/JP2008/061753 | Jun 2008 | US |
Child | 12369811 | US |